This invention relates to mechanical devices containing a bundle of independent, but interacting elements. The interactions among the elements provide switching actions that create differing effects for differing configurations of the elements.
This invention is a multistable mechanical switching device consisting of a compact bundle of independent extended elements, wherein a centrally-acting elastic containing means causes compaction and mutual constraint among the elements, allowing the existence of a number of possible, stable configurations of the elements. Application of sufficient force in appropriate spots on the perimeter of the bundle can overcome the energy barrier imposed by the containing means and result in a rapid rearrangement of the elements from one stable configuration into another. Interactive components or connecting means may be attached to or contained within the elements to provide different effects, depending upon the different relative arrangements of the interactive elements.
Each element can be in contact with up to 6 of its neighbors, allowing for a number of different possible interactions. One way these interactions can occur is through electrical contacts in the form of two or more circumferential rings spaced along the length of the elements.
This invention differs from U.S. Pat. No. 5,924,692 in that the bundle of elements may contain ordinary and active components. In the above patent, all the extended elements in close contact were not active and only xe2x80x9cinteractedxe2x80x9d mechanically. That is, the previously disclosed xe2x80x9cordinaryxe2x80x9d elements occupied space within the bundle, transferred mechanical forces, moved when sheared, impacted other elements when the bundle experienced a sudden rearrangement, and presented changing patterns due to their different markings. The manifestations of the sudden rearrangement of these ordinary elements were through seeing the change in the pattern of the differently marked ends of the elements, in feeling the rapid change in shape, and in hearing the snapping sound of the elements impacts. In the current invention, an xe2x80x9cactivexe2x80x9d element manifests itself in the above ordinary, mechanical visual, tactile and auditory ways and in addition may actively emit light, tones, or other signals. In contrast to the invention shown in U.S. Pat. No. 5,924,692, which used only ordinary elements, the current invention may employ a combination of ordinary and active elements. The ordinary elements perform the function of insulating, isolating, or separating active elements, preventing their activation until they come in contact as will be shown in the drawings. The active elements in the following drawings are biactive. Biactive elements are activated when they come in contact with another biactive element of appropriate type and remain activated until separated by an ordinary element. Triactive elements are activated when three elements of appropriate type come in contact with each other and remain activated until separated by an ordinary element. The generic term xe2x80x9cpolyactivexe2x80x9d will be used to refer to biactive, triactive, and higher type elements. A bundle of ordinary and active elements will be referred to hereafter as xe2x80x9cinteractivexe2x80x9d.
This invention differs from prior art switching devices in that the switching elements are independent and can change positions relative to each other. In prior art the switching elements are constrained relative to an insulating substrate and one or more of the elements move, pivot, rotate, snap or slide relative to the fixed elements. Here, all the elements are movable relative to each other.
The expansion of volume on shear is called xe2x80x9cvolumetric dilatancyxe2x80x9d. The analysis of the subject invention using elongated elements is particularly simple, since the shear occurs only in two, not three dimensions. Osborne Reynolds first described volumetric dilatancy in Reynolds, O., xe2x80x9cOn the Dilatancy of Media Composed of Rigid Particles in Contactxe2x80x9d Philosophical Magazine, 20 (S5), pp. 469-481, December 1885. In this article Reynolds describes the enclosing of a mass of solid particles or balls inside an elastic, closed envelope (latex balloon). Volumetric dilatancy is the tendency of a granular medium to expand upon shear. It has more recently been called a xe2x80x9clocking solidxe2x80x9d. This behavior can be most easily understood by the change that occurs when the plastic envelope of a vacuum-packed package of coffee is pierced. What was a solid, hard block of compressed coffee granules suddenly becomes a loose, pliable bag of free flowing granules.
Subsequently, Reynolds developed a theory of the structure of space, gravity, and electromagnetism in which volumetric dilatancy played an essential part: Reynolds, 0., Papers on Mechanical and Physical Subjects, Vol. 111, The Submechanics of the Universe, Cambridge: at the University Press, 1903, and Reynolds, 0., On an Inversion of Ideas as to the Structure of the Universe (The Rede Lecture, Jun. 10, 1902), Cambridge: at the University Press, 1903. In these documents, among much else, Reynolds explains light waves as transverse vibrations in a mechanical, granular medium (or aether) caused by xe2x80x9creversions of complex inequalitiesxe2x80x9d, i.e., by a snapping back of grains into close packing, an action that is made audible and tactual in the subject invention.
The previously described volumetric dilatant devices of Reynolds, while capable of producing a locking solid, use a plurality of uniform, near-spherical grains, not elongated elements of constant cross-section as taught herein. In addition, herein, the visibility of the ends of the elements allows changes in their relative positions and groupings to be seen and the interaction of the elements produces various other effects.
Examples of patents teaching compact bundle formation of elongated elements are found in U.S. Pat. Nos. 3,956,982 to Hill and Wynn, issued May 18, 1976 and 4,174,662 to Klusmier, issued Nov. 20, 1979. These patents describe devices to facilitate the assembly and fastening of bundles into a stable, unchanging configuration and do not deal with the dynamic and geometric properties of rearrangements of elements within the bundle nor their interactions as in the subject invention.
A theoretical physics approach is taken to mathematically describing arrangements of compacted finite systems of rigid elements in Stillinger, F. H. Jr. and Salzburg, Z. W., xe2x80x9cLimiting Polytope Geometry for Rigid Rods, Disks, and Spheresxe2x80x9d, pp.179-225, Journal of Statistical Physics, Vol. 1, No. 1, 1969. A polytope is the xe2x80x9climiting high-compression regionxe2x80x9d of a finite system of rods, disks or spheres. The subject invention provides a method for physically modeling and visually and tactually exploring the theoretical results for the 2-dimensional elongated element examples of Stillinger and Salzburg; but is in no way disclosed by their article.
It is believed that the subject invention is a novel way of implementing a multistable mechanical switching device with minimal means, inexpensively and effectively.